Coarctation & Transposition

Question 1

What is coarctation of aorta?

Answer 1

A narrowing of the aorta classified as just before (pre-ductal) or just after (post-ductal) the ductus arteriosus.

Question 2

What is the pathophysiology of coarctation of aorta?

Answer 2

Coarctation of the aorta will divert blood into the brachiocephalic artery supplying the right arm, and constrict flow to the more distal branches of the aorta that supply the right leg.

Question 3

How does coarctation of aorta present?

Answer 3

1. There is a difference in the saturations of the limbs. Radio-femoral delay is caused by blood flowing through collateral arterial circulation in the chest walls, which delays flow to the lower extremities.

=> weak / absent femoral pulses

2. It may present with an ejection systolic murmur heard loudest posteriorly, between the shoulders - heart sounds may be completely normal.
3. May be completely asymptomatic esp in younger patients.
   => may progress to cause left ventricular hypertrophy in teenagers and adults.
4. In teenagers or adults with coarctation, collateral circulation will develop with large intercostal arteries.
   => These may be visible as ‘rib notching’ on a chest x-ray.
5. Shocked: poor urine output, high lactate
6. Heart failure
7. No murmur
   * symptomatic when ductus arteriosus closes

Question 4

Association with Turner’s Syndrome:

=> 5% of babies with Turner syndrome are born with coarctation

=> Clinical findings: webbed neck, widely spaced nipples & coarctation of the aorta are most consistent with a diagnosis of Turner’s.

=> Turner syndrome = X0 karyotype. All Turner babies are girls.

Answer 4

INFO CARD

Question 5

How is coarctation of aorta managed?

Answer 5

ECHO monitoring

=> PROSTIN (prostaglandin)

=> may require management with a stent insertion or surgical repair.

Question 6

What is transposition of great arteries?

Answer 6

Transposition of the great arteries is a congenital cardiac defect where the aorta and pulmonary artery are swapped.

Question 7

What is the aetiology of transposition of great arteries?

Answer 7

In normal development, the aorto-pulmonary septum spirals.

In transposition of the great vessels, this spiral doesn’t happen, therefore:

=> aorta leaves the right ventricle

=> the pulmonary artery leaves the left ventricle

=> Blue blood that returns from the body is pumped back into the body

=> very cyanosed babies

=> highly dependent on ducts between right and left to mix blood

Question 8

How is transposition of great arteries managed?

Answer 8

Surgery <2 weeks